1b9ba00017
Some USB function drivers (e.g. f_mass_storage.c) need to delay or defer the data/status stages of standard control requests like SET_CONFIGURATION or SET_INTERFACE till they are done with their bookkeeping and are actually ready for accepting new commands to their interface. They can now achieve this functionality by returning USB_GADGET_DELAYED_STATUS in their setup handlers (e.g. set_alt()). The composite framework will then defer completion of the control transfer by not completing the data/status stages. This ensures that the host does not send new packets to the interface till the function driver is ready to take them. When the function driver that requested for USB_GADGET_DELAYED_STATUS is done with its bookkeeping, it should signal the composite framework to continue with the data/status stages of the control transfer. It can do so by invoking the new API usb_composite_setup_continue(). This is where the control transfer's data/status stages are completed and host can initiate new transfers. The DELAYED_STATUS mechanism is currently only supported if the expected data phase is 0 bytes (i.e. w_length == 0). Since SET_CONFIGURATION and SET_INTERFACE are the only cases that will use this mechanism, this is not a limitation. Signed-off-by: Roger Quadros <roger.quadros@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
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| acpi | ||
| asm-generic | ||
| crypto | ||
| drm | ||
| keys | ||
| linux | ||
| math-emu | ||
| media | ||
| mtd | ||
| net | ||
| pcmcia | ||
| rdma | ||
| rxrpc | ||
| scsi | ||
| sound | ||
| staging | ||
| target | ||
| trace | ||
| video | ||
| xen | ||
| Kbuild | ||